[PATCH V3 3/7] arm64/perf: Update struct pmu_hw_events for BRBE

From: Anshuman Khandual
Date: Thu Sep 29 2022 - 03:59:35 EST


A single perf event instance BRBE related contexts and data will be tracked
in struct pmu_hw_events. Hence update the structure to accommodate required
details related to BRBE.

Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
drivers/perf/arm_pmu.c | 1 +
include/linux/perf/arm_pmu.h | 26 ++++++++++++++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 59d3980b8ca2..16fda9a1229f 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -905,6 +905,7 @@ static struct arm_pmu *__armpmu_alloc(gfp_t flags)

events = per_cpu_ptr(pmu->hw_events, cpu);
raw_spin_lock_init(&events->pmu_lock);
+ events->branches = kmalloc(sizeof(struct brbe_records), flags);
events->percpu_pmu = pmu;
}

diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 3d427ac0ca45..ffce43ceb670 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -43,6 +43,16 @@
}, \
}

+/*
+ * Maximum branch records in BRBE
+ */
+#define BRBE_MAX_ENTRIES 64
+
+struct brbe_records {
+ struct perf_branch_stack brbe_stack;
+ struct perf_branch_entry brbe_entries[BRBE_MAX_ENTRIES];
+};
+
/* The events for a given PMU register set. */
struct pmu_hw_events {
/*
@@ -69,6 +79,22 @@ struct pmu_hw_events {
struct arm_pmu *percpu_pmu;

int irq;
+
+ /* Detected BRBE attributes */
+ bool v1p1;
+ int brbe_cc;
+ int brbe_nr;
+
+ /* Evaluated BRBE configuration */
+ u64 brbfcr;
+ u64 brbcr;
+
+ /* Tracked BRBE context */
+ unsigned int brbe_users;
+ void *brbe_context;
+
+ /* Captured BRBE buffer - copied as is into perf_sample_data */
+ struct brbe_records *branches;
};

enum armpmu_attr_groups {
--
2.25.1